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| United States Patent |
5,681,972
|
|
Hamann
, et al.
|
October 28, 1997
|
Process for preparing highly concentrated, free-flowing aqueous
solutions of betaines
Abstract
The invention relates to a process for preparing highly concentrated,
free-flowing and pumpable, aqueous solutions of betaines by quaternization
of compounds containing tertiary amine nitrogen with omega-halocarboxylic
acids by known processes, which is characterized in that a) 30-100
equivalent-%, based on the amount of omega-halocarboxylic acid used, of
Mg(OH).sub.2 and/or Ca(OH).sub.2 and b) 0-70 equivalent-%, based on the
amount of omega-halocarboxylic acid used, of one or more NaOH, KOH and
NH.sub.4 OH are added to the reaction mixture before or during the
quaternization reaction.
| Inventors:
|
Hamann; Ingo (Bad Orb, DE);
Kohle; Hans-Jurgen (Schluchtern, DE);
Wehner; Winfried (Neuhof, DE)
|
| Assignee:
|
Witco Surfactants GmbH (DE)
|
| Appl. No.:
|
413190 |
| Filed:
|
March 30, 1995 |
Foreign Application Priority Data
| Apr 12, 1994[DE] | 44 12 481.3 |
| Current U.S. Class: |
554/69; 554/52; 554/68 |
| Intern'l Class: |
C07C 231/00 |
| Field of Search: |
252/546
554/52,68,69
|
References Cited
U.S. Patent Documents
| 3225074 | Dec., 1965 | Cowen et al. | 260/404.
|
| 4832871 | May., 1989 | Bade | 252/546.
|
| 4861517 | Aug., 1989 | Bade | 252/546.
|
| 5204375 | Apr., 1993 | Kusakawa et al. | 514/784.
|
| Foreign Patent Documents |
| 0 353 580 | Feb., 1990 | EP.
| |
| 3 613 944 | Aug., 1987 | DE.
| |
| 3 726 322 | Dec., 1988 | DE.
| |
Primary Examiner: Geist; Gary
Assistant Examiner: Carr; Deborah D.
Attorney, Agent or Firm: Scully, Scott, Murphy & Presser
Claims
What is claimed is:
1. A process for preparing a highly concentrated, free-flowing and
pumpable, aqueous solutions of one or more betaines, comprising
quaternizing one or more compounds containing tertiary amine nitrogen of
the formula (I)
R.sup.3 --C(O)NH--(CH.sub.2).sub.m --NR.sup.4 R.sup.5 (I)
wherein R.sup.3 is alkyl or alkylene containing 6 to 20 carbon atoms and
0-3 carbon-carbon double bonds, and is optionally substituted with 1-6
hydroxyl groups, m is 1-3, and R.sup.4 and R.sup.5 are independently alkyl
containing 1 to 4 carbon atoms, with omega-halocarboxylic acid in the
presence of 0.5-5% by weight, based on the total mixture, of at least one
ionic or internal salt selected from the group consisting of
(Li.sup.1+).sub.a (X.sup.n-).sub.b, (Mg.sup.2+).sub.a (X.sup.n-).sub.b and
(Ca.sup.2+).sub.a (X.sup.n-).sub.b,
and one or more compounds of the general formula (IV)
##STR2##
where R R.sup.1, R.sup.2 are independently identical or different,
straight or branched alkyl radicals having 1-10 carbon atoms, optionally
substituted with 1 to 6 hydroxyl groups and n is 1-3,
wherein X.sup.n- is the radical of an organic or inorganic acid, n is 1-3,
a and b are integers, and the values of a, b and n are selected such that
the net charge of the compounds is neutral, and in the presence of the Na,
K or NH.sub.4 salt of the omega-halocarboxylic acid, wherein said one or
more ionic or internal salts is added before or during said
quaternization.
2. A betaine solution prepared according to claim 1, characterized in that
it contains at least 35% by weight of one or more compounds of the general
formula (III)
R.sup.3 --(C(O)NH--(CH.sub.2).sub.m --N.sup.+
(R.sup.4)(R.sup.5)(CH.sub.2).sub.y COO.sup.- (III)
wherein y is 1-3 and R.sup.3, m, R.sup.4 and R.sup.5 are as defined with
respect to formula (I); and
0.5-5% by weight of at least one lithium, magnesium or calcium salt with an
anion of the formula X.sup.n-.
3. A process for preparing a highly concentrated, free-flowing and
pumpable, aqueous solution of one or more betaines, comprising
quaternizing one or more compounds containing tertiary amine nitrogen of
the formula (I)
R.sup.3 --C(O)NH--(CH.sub.2).sub.m --NR.sup.4 R.sup.5 (I)
wherein R.sup.3 is alkyl or alkylene containing 6 to 20 carbon atoms and
0-3 carbon-carbon double bonds, and is optionally substituted with 1-6
hydroxyl groups, m is 1-3, and R.sup.4 and R.sup.5 are independently alkyl
containing 1 to 4 carbon atoms, with omega-halocarboxylic acid in the
presence of 0.5-5% by weight, based on the total mixture, of at least one
salt selected from the group consisting of
(Li.sup.1+).sub.a (X.sup.n-).sub.b, (Mg.sup.2+).sub.a (X.sup.n-).sub.b and
(Ca.sup.2+).sub.a (X.sup.n-).sub.b
wherein X.sup.n- is the radical of an organic or inorganic acid, n is 1-3,
a and b are integers, and the values of a, b and n are selected such that
the net charge of the compounds is neutral, and in the presence of the Na,
K or NH.sub.4 salt of the omega-halocarboxylic acid, wherein said salts
are added before or during said quaternization.
4. A process according to claim 3, characterized in that X.sup.n- is the
radical of a monobasic organic or inorganic acid.
5. A process according to claim 3, characterized in that X.sup.n- is the
anion Cl.sup.-.
6. A betaine solution prepared according to claim 3, characterized in that
it contains at least 35% by weight of one or more compounds of the general
formula (III)
R.sup.3 --(C(O)NH--(CH.sub.2).sub.m --N.sup.+
(R.sup.4)(R.sup.5)(CH.sub.2).sub.y COO.sup.- (III)
wherein y is 1-3 and R.sup.3, m, R.sup.4 and R.sup.5 are as defined with
respect to formula (I); and
0.5-5% by weight of at least one lithium, magnesium or calcium salt with an
anion of the formula X.sup.n-.
7. A betaine solution prepared according to claim 4, characterized in that
it contains at least 35% by weight of one or more compounds of the general
formula (III)
R.sup.3 --(C(O)NH--(CH.sub.2).sub.m --N.sup.+
(R.sup.4)(R.sup.5)(CH.sub.2).sub.y COO.sup.- (III)
wherein y is 1-3 and R.sup.3, m, R.sup.4 and R.sup.5 are as defined with
respect to formula (I); and
0.5-5% by weight of at least one lithium, magnesium or calcium salt with an
anion of the formula Xn.sup.n-.
8. A betaine solution prepared according to claim 5, characterized in that
it contains at least 35% by weight of one or more compounds of the general
formula (III)
R.sup.3 --(C(O)NH--(CH.sub.2).sub.m --N.sup.+
(R.sup.4)(R.sup.5)(CH.sub.2).sub.y COO.sup.- (III)
wherein y is 1-3 and R.sup.3, m, R.sup.4 and R.sup.5 are as defined with
respect to formula (I); and
0.5-5% by weight of at least one lithium, magnesium or calcium salt with an
anion of the formula X.sup.n-.
9. A process for preparing a highly concentrated, free-flowing and
pumpable, aqueous solution of one or more betaines, comprising
quaternizing one or more compounds containing tertiary amine nitrogen with
omega-halocarboxylic acid in the presence of a) 30-100 equivalent-%, based
on the amount of omega-halocarboxylic acid reacted, of one or more of
LiOH, Mg(OH).sub.2 and Ca(OH).sub.2 and b) 0-70 equivalent-%, based on the
amount of omega-halocarboxylic acid reacted, of one or more of NaOH, KOH,
and NH.sub.4 OH wherein said one or more hydroxides a) and, if present b)
is added before or during said quaternization.
10. A process according to claim 9, characterized in that the
omega-halocarboxylic acid used is chloroacetic acid.
11. A process according to claim 9, characterized in that the component a)
is 30-100 equivalent-%, based on the amount of omega-halocarboxylic acid
reacted, of LiOH.
12. A betaine solution prepared according to claim 9, wherein the solution
contains 30-100 equivalent-% of salts of lithium, magnesium, or calcium or
mixtures of one or more thereof.
13. A betaine solution prepared according to claim 10 wherein the solution
contains 30-100 equivalent-% of salts of lithium, magnesium, or calcium or
mixtures of one or more thereof.
14. A betaine solution prepared according to claim 11 wherein the solution
contains 3-100 equivalent-% of salts of lithium, magnesium, or calcium or
mixtures of one or more thereof.
15. A betaine solution prepared according to claim 9 containing
at least 35% by weight of one or more compounds of the general formula
R.sup.3 --C(O)NH--(CH.sub.2).sub.1-3 --N.sup.+
(R.sup.4)(R.sup.5)--(CH.sub.2).sub.1-3 C(O)O.sup.- (III)
wherein R.sup.3 is alkyl or alkylene containing 6 to 20 carbon atoms and
0-3 carbon-carbon double bonds, and is optionally substituted with 1-6
hydroxyl groups, and R.sup.4 and R.sup.5 are independently alkyl
containing 1 to 4 carbon atoms;
4-8% by weight if at least one lithium, magnesium, or calcium salt; and
water to 100%.
16. A betaine solution prepared according to claim 10 containing
at least 35% by weight of one or more compounds of the general formula
R.sup.3 --C(O)NH--(CH.sub.2).sub.1-3 --N.sup.+
(R.sup.4)(R.sup.5)--(CH.sub.2).sub.1-3 C(O)O.sup.- (III)
wherein R.sup.3 is alkyl or alkylene containing 6 to 20 carbon atoms and
0-3 carbon-carbon double bonds, and is optionally substituted with 1-6
hydroxyl groups, and R.sup.4 and R.sup.5 are independently alkyl
containing 1 to 4 carbon atoms;
4-8% by weight if at least one lithium, magnesium, or calcium salt; and
water to 100%.
17. A betaine solution prepared according to claim 11 containing
at least 35% by weight of one or more compounds of the general formula
R.sup.3 --C(O)NH--(CH.sub.2).sub.1-3 --N.sup.+
(R.sup.4)(R.sup.5)--(CH.sub.2).sub.1-3 C(O)O.sup.- (III)
wherein R.sup.3 is alkyl or alkylene containing 6 to 20 carbon atoms and
0-3 carbon-carbon double bonds, and is optionally substituted with 1-6
hydroxyl groups, and R.sup.4 and R.sup.5 are independently alkyl
containing 1 to 4 carbon atoms;
- 8% by weight if at least one lithium, magnesium, or calcium salt; and
water to 100%.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a process for preparing highly
concentrated, free-flowing aqueous solutions of betaines, which have
solids contents of up to 50% by weight.
In recent years, betaines have become established in the cosmetic industry
as a significant constituent of formulations, in particular for hair and
body cleansing. They have the ability to form a dense and creamy foam
which remains stable over a long period of time even in the presence of
other surfactants, soaps and additives, together with recognized good
cleansing properties without any irritating side effects, even for
sensitive skin.
The preparation of betaines is comprehensively described in the relevant
patent and specialist literature (e.g., U.S. Pat. No. 3,225,074). In
general, compounds containing tertiary amine nitrogen atoms are here
reacted with omega-halocarboxylic acids or salts thereof in aqueous or
water-containing media. The compounds containing tertiary amine nitrogen
atoms used are, in particular, one or more fatty acid amides of the
general formula (I)
R.sup.3 --CONH--(CH.sub.2).sub.m --NR.sup.4 R.sup.5 (I)
where R.sup.3 is the alkyl radical, or alkylene radical with 1-3
carbon-carbon double bonds, of a fatty acid, which can if desired, be
branched, if desired contain multiple bonds and, if desired, contain 1-6
hydroxyl groups, and R.sup.4 and R.sup.5 are identical or different alkyl
radicals having 1-4 carbon atoms and m can be 1-3.
The alkyl or alkylene radical R.sup.3 can here be derived from the natural
or synthetic fatty acids having 6-20 carbon atoms, preferably from the
natural plant or animal fatty acids having 8-18 carbon atoms, and also
their naturally occurring specially set mixtures with one another or among
one another.
Suitable fatty acids are, for example, caproic acid, caprylic acid, capric
acid, lauric acid, palmitic acid, stearic acid, linoleic acid, linolenic
acid and ricinoleic acid.
Preference is given to the naturally occurring fatty acid mixtures having a
chain length of 8-18 carbon atoms, such as coconut oil acids or palm
kernel oil acids, which can, if desired, be hardened by suitable
hydrogenation methods.
These fatty acids or fatty acid mixtures are converted into the fatty acid
amides having tertiary nitrogen atoms, of the general formula (I), by
means of the conventional condensation reaction at 140.degree.-200.degree.
C. with one or more amines of the general formula (II)
H.sub.2 N--(CH.sub.2).sub.m --NR.sup.4 R.sup.5 (II)
in which R.sup.4 and R.sup.5 and m are as defined for the formula (I).
The subsequent quaternization reaction to give betaines of formula (III)
R.sup.3 --C(O)NH--(CH.sub.2).sub.m --N.sup.+ R.sup.4 R.sup.5
(CH.sub.2).sub.y C(O)O.sup.-
wherein R.sup.3, R.sup.4, R.sup.5 and m are as defined for the formulae (I)
and (II) and y can be 1, 2 or 3, can be carried out according to the
processes known in the literature.
In general, omega-haloalkylcarboxylic acids, preferably the sodium salt of
chloroacetic acid, are here added in aqueous medium to the fatty acid
amide of the formula (I) and the quaternization is carried out in a
reaction taking a number of hours at about 80.degree.-100.degree. C.
Depending on the fatty acid or fatty acid mixture used, a minimum amount
of water has to be present to maintain stirrability as the reaction
proceeds. The commercial betaine concentration of the solutions prepared
in this way is therefore about 30% by weight or below.
However, to save storage and transport costs and also for formulation
reasons in further processing, a higher concentration is greatly desired
in many cases.
In the past, therefore, proposals were made for a number of processes which
were supposed to solve this problem. Thus, DE-C 3 613 944 discloses a
process in which the quaternization is carried out in a polar organic
solvent having a water content of 20% by weight, and the solvent is then
completely or partially removed by distillation, and the concentration is
then adjusted to that desired using a solvent which is usable in the
application.
Apart from the process being technically complicated and expensive, organic
solvents are often undesired in further processing in cosmetic
formulations.
Although the process described in DE-C 3 726 322 can be carried out without
organic solvents, the amount of water required for the quaternization
reaction has to be removed again from the reaction product by
distillation, with the pH of the solution having to be adjusted by
relatively high amounts of acid, before or after adjustment to the desired
concentration, to values of 1-4.5 which are atypical of skin.
According to EP-A 0 353 580, non-ionogenic, water-soluble surfactants are
added to the reaction mixture of fatty acid amide and haloalkylcarboxylic
acid before or during the quaternization reaction or to the solution of
the betaine obtained, in such amounts that the finished solution contains
3-20% by weight of water-soluble surfactants.
The non-ionogenic surfactants used are polyoxyethylene ethers which have to
contain 10-250 oxyethylene units for sufficient water solubility.
However, polyoxyethylene ethers having relatively high proportions of
oxyethylene units have proven not to be unproblematical in respect of
their biodegradability.
There has therefore been a continuing need for highly concentrated,
free-flowing and pumpable, aqueous solutions of betaines, which are free
of lower alcohols such as methanol, ethanol, propanol or isopropanol.
BRIEF SUMMARY OF THE INVENTION
It has now surprisingly been found that free-flowing and pumpable solutions
of betaines having a concentration of up to about 45% by weight, based on
dry substance, can be prepared from the reaction mixture of fatty acid
amide and omega-haloalkylcarboxylic acid by known processes if alkaline
earth metal hydroxides such as, in particular, Mg(OH).sub.2 and/or
Ca(OH).sub.2 are added during the quaternization reaction.
The invention accordingly provides a process for preparing highly
concentrated, free-flowing and pumpable, aqueous solutions of betaines by
quaternizing one or more compounds containing tertiary amine nitrogen with
one or more omega-halocarboxylic acids which is characterized in that the
quaternization is carried out in the presence of a) 30-100 equivalent-%,
based on the amount of omega-halocarboxylic acid reacted, of Mg(OH).sub.2
and/or Ca(OH).sub.2 and b) 0-70 equivalent-%, based on the amount of
omega-halocarboxylic acid reacted, of one or more of NaOH, KOH and
NH.sub.4 OH, which hydroxide compound or compounds are added to the
reaction mixture before or during the quaternization reaction.
The invention further provides for the modification of this process, which
is characterized in that the component a) used is 30-100 equivalent-%,
based on the amount of omega-halocarboxylic acid used, of LION.
DETAILED DESCRIPTION OF THE INVENTION
In carrying out the process of the invention, the initially charged
omega-halocarboxylic acid is neutralized with a mixture of sodium
hydroxide and magnesium and/or calcium hydroxide, and the quaternization
reaction of the one or more compounds of formula (I) is carried out by
reaction for a number of hours in an aqueous medium at
80.degree.-100.degree. C.
A further process variant for preparing highly concentrated, free-flowing
and pumpable, aqueous solutions of betaines comprises carrying out the
reaction by any of the known processes using haloacetic acid such as
chloroacetic acid and NaOH or using the sodium salt of e.g. chloroacetic
acid, with the modification that lithium, magnesium or calcium salts,
alone or in admixture, are added as viscosity regulators before or during
the quaternization reaction.
The invention accordingly further provides a process for preparing highly
concentrated, free-flowing and pumpable, aqueous solutions of betaines by
quaternization of compounds containing tertiary amine nitrogen with
omega-halocarboxylic acids according to known processes, which is
characterized in that 0.5-5% by weight, based on the total mixture, of at
least one of the salt compounds
(Li.sup.1+).sub.a (X.sup.n-).sub.b, (Mg.sup.2+).sub.a (X.sup.n-).sub.b,
(Ca.sup.2+).sub.a (X.sup.n-).sub.b,
where X.sup.n- is the radical of an organic or inorganic acid, and n is
1-3, and a and b are integers, wherein a, b and n are selected such that
the salt compounds are neutral in charge, is added to the mixture of fatty
acid amide of the general formula (I) and the Na, K or NH.sub.4 salt of
the omega-halocarboxylic acid before or during the quaternization
reaction.
X.sup.n- is the anion of a monobasic or polybasic organic acid, in
particular monobasic to tribasic acids, insofar as they form water-soluble
salts with Li, Mg and/or Ca, such as C.sub.1 -C.sub.5 -monocarboxylic
acids, preferably acetic acid.
According to the invention, however, preference is given to using LiCl,
MgCl.sub.2 and/or CaCl.sub.2 in the form of the anhydrous salts or the
hydrates.
The total amount of the one or more compounds (Li.sup.+1).sub.a
(X.sup.n-).sub.b, (Mg.sup.2+).sub.a (X.sup.n-).sub.b and (Ca.sup.2+).sub.a
(X.sup.n-).sub.b is between 0.5-5% by weight, based on the total mixture.
A further process variant comprises completely or partially replacing all
or some of the Li.sup.+, Mg.sup.2+ and/or Ca.sup.2+ salts by one or more
compounds of the general formula (IV)
##STR1##
wherein R, R.sup.1 and R.sup.2 are independently identical or different
straight or branched alkyl radicals having 1-10 carbon atoms optionally
substituted with 1-6 hydroxyl groups, in particular methyl radicals, and n
is 1-3 and n is preferably 1, with mixtures of 0.5-2% by weight of one or
more of the aforementioned salt compounds of Li, Mg and/or Ca, and 0.5-5%
by weight of betaine being preferred according to the invention.
Compounds of the general formula (IV) which can also be used according to
the invention are quaternization products of dimethylethanolamine,
methyldiethanolamine or alkyl (C.sub.2 -C.sub.10)-dimethytamine and
monochloroacetic acid, but in particular the trimethylglycine or "betaine"
occurring naturally in sugar beet (Beta vulgaris).
These compounds can be added to the reaction mixture as mixtures together
with the salts, simultaneously with salt addition or after salt addition,
in amounts of 1-5% by weight, based on the aqueous solution, with a total
content of (salt+betaine) being above 5 to 7% by weight, based on the
aqueous solution, generally bringing no advantages.
According to the invention, preference is given to mixtures of 0.5-2% by
weight of one or more of the aforementioned compounds of Li, Mg and/or Ca,
and 0.5-5% by weight of betaine.
The carrying out of the process follows the processes known in the prior
art, with the significant change comprising the addition of the one or
more alkaline earth metal salts and/or the LiCl before or during the
quaternization reaction.
The preferred procedure according to the invention is to neutralize the
initially charged omega-halocarboxylic acid with sodium hydroxide and to
add 0.5-5.0% by weight, based on the total mixture, of one or more of
LiCl, MgCl.sub.2 and/or CaCl.sub.2 before or during the reaction, which
takes a number of hours, in an aqueous medium at 80.degree.-100.degree. C.
Analytical methods
Dry content:
The dry content is determined by drying the material at 105.degree. C. to
constant weight. These values are determined by the standard methods of
the German Association for Fat Chemistry (DGF): B-II.
Acid number (AN):
The acid number is a measure of the free acids contained in fats and
technical grade fatty acids. It indicates the number of milligrams of
potassium hydroxide which is required to neutralize 1 gram of substance or
technical grade fatty acids (mg KOH/g). These values are determined by the
standard methods of the German Association for Fat Chemistry (DGR): D-IV
2a.
Ester number (EN):
The ester number is a measure of the esters contained in fats and technical
grade fatty acids. It indicates the number of milligrams of potassium
hydroxide which is required to saponify 1 gram of substance or technical
grade fatty acids (mg KOH/g). These values are determined by the standard
methods of the German Association for Fat Chemistry (DGF): C-V 4.
Total amine number (TAN), tertiary amine number (TerAN):
The total amine number indicates the number of milligrams of potassium
hydroxide which are equivalent to the total basicity of 1 gram of the
amine compound (mg KOH/g).
The tertiary amine number indicates the number of milligrams of potassium
hydroxide which are equivalent to the tertiary amine basicity of 1 gram of
the amine compound (mg KOH/g).
The values are determined by the American Oil Chemists Society (A.O.C.S.)
Official Method Tf 2a-64.
Chloride:
The chloride content is determined potentiometrically against a standard
silver nitrate solution. The electrode used is a combination silver
chloride electrode. The values are determined by the standard methods of
the German Association for Fat Chemistry (DGF): H-III 9.
EXAMPLES
Example 1
Preparation of the aminamide:
In a reactor fitted with stirrer, thermometer and distillation attachment,
98.0 kg of hardened coconut oil were admixed under an inert gas atmosphere
with 56.8 kg of dimethylaminopropylamine and heated to
150.degree.-160.degree. C. and boiled under reflux. After the amidation
was complete (ester number <10 mg KOH/g), the excess amine was distilled
off in vacuo at this temperature. The distillation was complete, since the
difference between the total amine number and tertiary amine number was
less than 3 mg KOH/g. The aminamide obtained had a TAN of 170.6 mg KOH/g,
a TerAN of 168.6 mg KOH/g and an ester number of 2.8 mg KOH/g.
Example 2
97.3 g of monochloroacetic acid were diluted with 504 g of water while
cooling in a 1-liter flask fitted with stirrer, internal thermometer and
pH electrode and carefully neutralized with 27.8 g of lithium hydroxide.
After addition of 320 g of the aminamide from Example 1, the reaction
mixture was stirred at 80.degree.-90.degree. C., the pH being kept between
8 and 8.5. For this purpose, a further total of 2.9 g of lithium hydroxide
were required. After a reaction time of about 9 hours, the alkylation was
complete. A betaine mixture had formed and was allowed to cool to
50.degree. C., and the pH was adjusted to 5.4 using 5.2 g of citric acid.
The final product was a clear liquid having a viscosity of 130 mPas at
20.degree. C., a dry residue of 45.7 and a chloride content of 3.8%.
Example 3
97.3 g of monochloroacetic acid were diluted with 515 g of water while
cooling in a 1 liter flask fitted with stirrer, internal thermometer and
pH electrode and carefully neutralized with 31 g of magnesium hydroxide.
After addition of 320 g of the aminamide from Example 1, the reaction
mixture was stirred at 80.degree.-90.degree. C., the Ph being kept between
8 and 8.5. For this purpose, a further total of 2.9 g of magnesium
hydroxide were required. After a reaction time of about 8 hours, the
alkylation was complete. A betaine mixture had formed and was allowed to
cool to 50.degree. C., and the pH was adjusted to 5.1 using 6.5 g of 50%
strength citric acid solution.
The final product was a clear liquid having a viscosity of 90 mPas at
20.degree. C., a dry residue of 45.0% and a chloride content of 3.8.
Example 4
97.3 of monochloroacetic acid were diluted with 520 g of water while
cooling in a 1 liter flask fitted with stirrer, internal thermometer and
pH electrode and carefully neutralized with 38.9 g of calcium hydroxide.
After addition of 320 g of the amminamide from Example 1, the reaction
mixture was stirred at 80.degree.-90.degree. C., the pH being kept between
8 and 8.5. For this purpose, a further total of 2.9 g of calcium hydroxide
were required. After a reaction time of about 8 hours, the alkylation was
complete. A betaine mixture had formed and was allowed to cool to
50.degree. C. and the pH was adjusted to 5.9 using 3 g of citric acid.
The final product was a clear liquid having a viscosity of 170 mPas at
20.degree. C., a dry residue of 45.1% and a chloride content of 3.6%.
Example 5
97.5 g of monochloroacetic acid were diluted with 500 g of water while
cooling in a 1 liter flask fitted with stirrer, internal thermometer and
pH electrode and carefully neutralized with 7.5 g of magnesium hydroxide
and 63 g of sodium hydroxide solution (50%). After addition of 320 g of
the aminamide from Example 1, the reaction mixture was stirred at
80.degree.-90.degree. C., the pH being kept between 8 and 8.5. For this
purpose, a further total of 6.0 g of sodium hydroxide (as 50% strength
solution) were required. After a reaction time of about 8 hours, the
alkylation was complete. A betaine mixture had formed and was allowed to
cool to 50.degree. C. and the pH was adjusted to 5.4 using 3.5 g of citric
acid.
The final product was a clear liquid having a viscosity of 128 mPas at
20.degree. C., a dry residue of 44.6% and a chloride content of 3.6%.
Example 6
97.3 g of monochloroacetic acid were diluted with 500 g of water while
cooling in a 1 liter flask fitted with stirrer, internal thermometer and
pH electrode and carefully neutralized with 15 g of magnesium hydroxide
and 44 g of sodium hydroxide solution (50%). After addition of 320 g of
the aminamide from Example 1, the reaction mixture was stirred at
80.degree.-90.degree. C., the pH being kept between 8 and 8.5. For this
purpose, a further total of 4.6 g of sodium hydroxide (as 50% strength
solution) were required. After a reaction time of about 8 hours, the
alkylation was complete. A betaine mixture had formed and was allowed to
cool to 50.degree. C. and the pH was adjusted to 5.6 using 3.5 g of citric
acid.
The final product was a clear liquid having a viscosity of 210 mPas at
20.degree. C., a dry residue of 45.9% and a chloride content of 3.7%.
Example 7
97.3 g of monochloroacetic acid were diluted with 500 g of water while
cooling in a 1 liter flask fitted with stirrer, internal thermometer and
pH electrode and carefully neutralized with 82 g of sodium hydroxide
solution (50%). After neutralization, the sodium chloroacetate mixture was
admixed with 52.4 g of magnesium chloride hexahydrate and heated to
70.degree.-80.degree. C. After addition of 320 g of the aminamide from
Example 1, the reaction mixture was stirred at 80.degree.-90.degree. C.,
the pH being kept between 8 and 8.5. For this purpose, a further total of
10.3 g of sodium hydroxide (as 50% strength solution) were required. After
a reaction time of about 8 hours, the alkylation was complete. a betaine
mixture had formed and was allowed to cool to 50.degree. C. and the pH was
adjusted to 5.8 using 5.4 g of citric acid.
The final product was a clear liquid having a viscosity of 112 mPas at
20.degree. C., a dry residue of 45.1% and a chloride content of 5.1%.
Example 8
97.3 g of monochloroacetic acid solution were carefully neutralized with 82
g of sodium hydroxide solution (50%) while cooling in a 1 liter flask
fitted with stirrer, internal thermometer and pH electrode. After
neutralization, the sodium chloroacetate mixture was admixed with 26 g of
magnesium chloride hexahydrate and heated to 70.degree.-80.degree. C.
After addition of 320 g of the aminamide from Example 1, the reaction
mixture was stirred at 80.degree.-90.degree. C., the pH being kept between
8 and 8.5. For this purpose, a further total of 5.3 g of sodium hydroxide
(as 50% strength solution) were required. After a reaction time of about 8
hours, the alkylation was complete. A betaine mixture had formed and was
allowed to cool to 50.degree. C. and the pH was adjusted to 5.9 using 3.5
g of citric acid.
The final product was a clear liquid having a viscosity of 107 mPas at
20.degree. C., a dry residue of 44.4% and a chloride content of 4.3%.
Example 9
97.3 g of monochloroacetic acid were diluted with 535 g of water while
cooling in a 1 liter flask fitted with stirrer, internal thermometer and
pH electrode and carefully neutralized with 32 g of magnesium hydroxide.
After addition of 24.3 g of trimethylglycine and 320 g of the amminamide
from Example 1, the reaction mixture was stirred at 80.degree.-90.degree.
C., the pH being kept between 8 and 8.5. For this purpose, a further total
of 7.3 g of magnesium hydroxide were required. After a reaction time of
about 8 hours, the alkylation was complete. A betaine mixture had formed
and was allowed to cool to 50.degree. C. and the pH was adjusted to 5.7
using 18 g of citric acid monohydrate.
The final product was a clear liquid having a viscosity of 132 mPas at
20.degree. C., a dry residue of 45.4% and a chloride content of 3.5%.
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